joi2019_ho_t2.cpp: In function 'int main(int, const char**)':
joi2019_ho_t2.cpp:19:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
19 | scanf("%d%d", &N, &M);
| ~~~~~^~~~~~~~~~~~~~~~
joi2019_ho_t2.cpp:25:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
25 | scanf("%d%d", &a, &b);
| ~~~~~^~~~~~~~~~~~~~~~
joi2019_ho_t2.cpp:31:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
31 | scanf("%d", &a);
| ~~~~~^~~~~~~~~~